1. Field of the Invention
The present invention relates to a clip assembly comprising clips having a U-shaped cross-section which are connected together by plastic wires to provide a clip stack for mounting in a magazine of a tool which separates and crimps the clips around metal wires, such as coils of a spring in a mattress or an automobile seat.
2. Description of the Prior Art
Heretofore it has been proposed in U.S. Pat. No. 3,722,670 to provide a clip stack where the clips are held together by two plastic wires and where the plastic wires are pressed into notches in the side edges of a plurality of aligned U-shaped clips to provide the clip stack which is insertable into a magazine of a tool that is adapted to cut each clip from the stack and crimp each U-shaped clip around two or more metal wires or rods.
There has also heretofore been proposed a U-clip assembly in U.S. Pat. No. 4,508,220. This patent teaches a U-shaped clip assembly and method of producing same wherein the clips are held together in an assembly or stack by two metal wires which are welded to the outer bight or crown portion of inverted U-shaped clips.
As will be described in greater detail hereinafter, the resilient clip assembly of the present invention provides a plurality of clips which have generally parallel spaced slots formed transversely of the clip across the outer inverted side of the bight or crown portion of each clip. Then, a plastic wire is inserted in each row of slots in an aligned row of the U-shaped clips. Next, pressure is applied to the side edges of each clip at the bight portion thereof to crimp the metal about each slot partly around the plastic wire received therein.
The resilient clip assembly of the present invention has the advantage that it is easier to form two slots in the inverted bight or crown of the clip than to form four notches in the side edges of a clip, as disclosed in U.S. Pat. No. 3,722,670.
Furthermore, the plastic wire cord is not pinched or mechanically held in the notches of the clip disclosed in U.S. Pat. No. 3,722,670 and is held therein merely by friction.
Still further, due to the location of the notches in the side edges of the clip, the clip stack of U.S. Pat. No. 3,722,670 is not easily adapted to clips of different size, whereas the resilient clip assembly of the present invention can be adapted to any size clip.
With respect to the U-clip assembly disclosed in U.S. Pat. No. 4,508,220, the welding of wires to the outer side of the crown or bight portion of each of the clips in the clip assembly requires a cleaning of the steel, since welding requires clean surfaces.
Furthermore, the steel wire has no memory, and if the strip of clips in the assembly is twisted or deformed, it remains in that condition, which can result in jamming of the clips in the magazine of the tool.
Also, cutting of a metal wire will result in eventual dulling of the cutting element, and it will require replacement. Additionally, wire chips are formed in cutting wires and contaminate automated mattress assembly equipment as disclosed in U.S. Pat. No. 4,829,643 resulting in equipment malfunctions. Still further, the cut wire edges can sometimes be inadvertently engaged by an operator causing injury.
The resilient clip assembly of the present invention avoids these possible limitations of the prior art U-clip assembly disclosed in U.S. Pat. No. 4,508,220.